OCTA operates about 475 buses that carry 225,000 riders daily; Metrolink carries an additional 11,000 daily riders in the county. Officials created a contingency plan in case a disruption in the U.S. oil supply leads to more OCTA riders.

The concern began when gasoline prices soared last summer but did not do their traditional drop in the fall, said OCTA spokesman Joel Zlotnik.

The crisis plan calls for creating a 150-bus contingency fleet by December; taking an option to buy 57 more buses; promoting alternative commutes, such as car pools and van pools; and possibly lowering Metrolink fares for shorter runs.

During the 1970s, fuel was rationed and at times unavailable. By contrast, fuel remains available and demand for transit remains below previous years, Zlotnik said.

Metrolink ridership increased 5% through the first quarter of the year, and there is anecdotal evidence that ridership climbed during the first two weeks in June. Zlotnik said OCTA will have a clearer picture at the end of the month.

Passenger counts on express buses, which run on freeways between Riverside, Orange and Los Angeles counties, are up nearly 19% since January. Transfers from Metrolink stations to fixed-route buses in Orange County are up 25%.

Whether OCTA has enough fuel is not a big concern, said fleet manager Beth McCormick. In the 10 years, OCTA has bought buses that use liquid and compressed natural gas to help move the fleet from diesel to cleaner-burning fuels.

OCTA has long-term fuel contracts, and during a crisis, buses usually get fuel priority because they conduct a public service, McCormick said.